Stormwater runoff from impervious surfaces is a serious environmental problem due to the pollutants contained in the water and the additional volume of runoff that is created because the impervious surface no longer allows water to enter the ground. While the field is replete with technologies that clean or filter the water and some that attenuate or slow down the water, there are few that combine all of the above.
The present invention is a unique method of treating and routing stormwater runoff that enables a highly efficient, effective, and compact means of treating the runoff.
Stormwater runoff has a significant variation in intensity: from a light drizzle with virtually no measureable runoff to an extreme intensity localized thunderstorm with flash flooding runoff levels. To remove the level of pollutants required to meet today's regulations, filtration is most often required.
With a filter having a limited flow rate, it takes a substantial filtration area to treat peak flows. The filtration area can be reduced by storing the water prior to filtration and filtering it over time. For example, storage and filtering over a 24 hour period. This storage and delayed release reduces the impacts of peak intensity storms and at the same time reduces the risk of downstream flooding
In addition, with the focus on reduction of runoff through ground water replenishment or infiltration, water can be recharged through placing it in a stone pit or equivalent to allow it to percolate into the ground. However this also takes time. A very important element to the longevity of the recharge is that only clean water is recharged because the pollutants will quickly occlude the surface soils in the recharge area and diminish its effectiveness.